Pondering... Fiberglass question

[starleen2]

Exactly Mike; unless to began with overthickness wood and planed it down to the exact thickness of the foam, you have an irregular surface. I could see putting on one layer, then using filler putty to level; then apply top layers. However, just laying over framework and foam is gonna leave an irregular surface

OK, then How about bonding 1/4 foam to the outside - then do the fiberglass - that should give you a smooth sruface? senn some 1/4 sheet of foam

[Ageless]

Mike; with the exception og bagging it and drawing a vacuum; that's how we did it at Boeing.

Starleen; that would work, but you would have a rough suface which you would need to sand and recoat a couple times. If you could lay-up a skin on a table like Mike suggests then bond that to your framewoork/foam core; then you get the smooth surface. This would be for any curved surfaces. Then all that would be left would be to apply cloth/resin to corners; sand and recoat.

[ktm_2000]

I built my camper similar to what he is asking but I put 5.5mm luan on the outside and glassed over it.

I'm in the finishing stages and have spent more time and effort glassing and fairing the outside than I did building and assembling the body of the camper.

[RogHodge]

Having reviewed the problem it sounds what you are looking for is;
“I'm Just looking for a seamless method that will allow me to radius the edges and have a smooth finish on the exterior.”

A worthy goal no doubt- In my limited experience with fiberglass, that stuff conforms to the surface upon which it is laid. Smooth would require some work, and a few gallons of bondo- I like the concept that mike had about a waxed table, the surface could be like a mirror - The effort involved would be prohibitive for me. Also any gaps between the glass and the frame would bubble and give you fits. If you encase the entire trailer with ¼ foam you could have a smooth surface- maybe. Foam and fiberglass lends itself to compression dings- think surfboard. Unless the glass is thick, which also makes it heavier. Vacuum bagging is a good way to get adhesion and eliminate voids- we use this for relatively small parts- Ageless- ever bag something the size of a TTT – I imagine the ‘bag’ would be huge, then how to draw a vacuum?!? Well out of my league.

Doug gets a smooth surface and spiffy round corners- How does he do it? Magic! No wait not magic- a router. I think that a guy could use 1/8 ply for a skin over ¾ frame and, with judicious placement of glue, brads, and other fasteners, still have room for a 1” radius on the edge. A combination of mat and cloth over that would be slick. If the frame had more beef in the corners you could have a more generous radius.
Regardless of the construction method there will be seams to deal with-
You clearly have the skills to deal with wood- If you want to experiment with glass you could make some boxes or small wall/roof sections to play with the material- far better to waste a sheet or two experimenting than to go full scale with an unproven method.

As they say- my 2cents- I shall watch with great anticipation.

[Ageless]

Ageless- ever bag something the size of a TTT

Actually; bagged parts the size of a 40' Airstream at Boeing

[RogHodge]

Ageless- Don’t mean to cast aspersions on your skills or experience- More of curiosity.
Sheets of G10 would be fantastic if they weren’t so stinking expensive- I have seen large sheets of glass/honeycomb/glass that were outrageously light and strong. No idea where a person could get it though. So does NASA have a dumpster into which we could dive?

[Ageless]

Not top secret stuff; goes back to the 1950s

http://www.hexcel.com/

[starleen2]

. . . Regardless of the construction method there will be seams to deal with-
You clearly have the skills to deal with wood- If you want to experiment with glass you could make some boxes or small wall/roof sections to play with the material- far better to waste a sheet or two experimenting than to go full scale with an unproven method.

As they say- my 2cents- I shall watch with great anticipation.

I still have some resin and Glass left iover - guess I'll try some sperimentin'

[Lou Park]

I'm no expert but why can't you take the pink foam, fiberglass both side (1 on 1 day the other on the next day) without wood structure? Once you do this, you should be able to cut it to size and fiberglass the ends. This should make for a very rigid panel ready to finish.
Lou

[Ageless]

Lou, have done this. Lay out sheet of plastic. Lay the panel down. Lay a sheet of plywood on top and apply weight.

Next day; f/g opp side and repeat

[starleen2]

I'm no expert but why can't you take the pink foam, fiberglass both side (1 on 1 day the other on the next day) without wood structure? Once you do this, you should be able to cut it to size and fiberglass the ends. This should make for a very rigid panel ready to finish.
Lou

The thing you have to remember is that where you put a window, door, or cabinets - you have to put something for it to attach to. The foam core doesn't offer much to screw to. The core will compress between the fiberglass if you try to bolt through. That is why they are needed - you can certainly debate about this - but the means to do it with em' are far beyond what I'm willing to try.

[Ageless]

You could always layout window locations, cut away and add a wood filler prior to glassing. Cut the window opening oversize, cut a framing about 3/4" wide and insert into foam core.

[Lou Park]

You could always layout window locations, cut away and add a wood filler prior to glassing. Cut the window opening oversize, cut a framing about 3/4" wide and insert into foam core.

Also, if you start out with 1.5 or 2" thick foam, you could layout the cabinet and wall, and shelf locations and insert 3/4" furring into the foam then lay the fiberglass over.

[laoutdoorsman]

does fiberglass resin bond to the foam well??

[WesGrimes]

Mike,

Polyurethane foam will bond with laminating resin well as long as there is enough saturation and no air pockets. Other types of foam like EPS will create a nice toxic paste.

When you guys figure out the best way to do this, come over and show me! I am in the middle of attempting this.

Btw, Foam is about the weakest core material that you could use. Balsa is common and cheap. Honeycomb is great, but not very cheap...

Check out fibreglast.com. They have a great information center on their site complete with videos on youtube. Search fibreglast on youtube...